This invention relates to rod end bearings. Such bearings are of the type required to connect together two rods, components or assemblies with a spherical or ball type joint.
Usually such moulded race bearings comprise three parts, namely an outer shell part, an inner ball part and a moulded race situated between the outer shell part and the inner ball part. Suitably the outer shell part and the inner ball part are formed from leaded steel while the moulded race is a suitable injection moulded reinforced nylon.
Various problems exist with the manufacture and use of the known bearings. These problems include the possibility of the rod ends pulling apart where significant axial overloading takes place and also ensuring sufficient accuracy to prevent the existence of play and to provide a smooth free running bearing that does not introduce excessive friction into the linkage assembly.
The present invention seeks to provide a new and improved rod end bearing having a good accuracy and which is resistant to axial overloading.
According to a first aspect of the invention, there is provided a rod end bearing comprising an outer shell part defining a generally spherical inner surface and defining a pair of diametrically opposed openings, an inner ball part seated within said outer shell part, the outer diameter of said ball part being greater than the diameter of one of said diametrically opposed openings and being only slightly less than the diameter of the other of said diametrically opposed openings and a moulded bearing race located between said inner ball part and said outer shell part.
The moulded bearing race may comprise injection moulded polyurethane.
According to a second aspect of the invention, there is provided a rod end bearing comprising an outer shell part having a generally spherical inner surface, an inner ball part seated within the outer shell part and a moulded bearing race located between the outer shell part and the inner ball part and formed from injection moulded polyurethane.
The outer shell part may have a pair of diametrically opposed openings and the outer diameter of the inner ball part is only slightly less than the diameter of at least one of the diametrically opposed openings.
The diameter of the other opening in the outer shell part is preferably less than the outer diameter of the inner ball part.
The inner ball part may comprise a generally spherical body having flattened side parts which are diametrically opposite to each other, the body being penetrated by a bore which extends through the centre of the sphere of the spherical body from one of the flat parts to the other flat part.
The outer shell part may be provided with a radially extending projection for the attachment of a rod end thereto and the projection may comprise a socket into which the rod end can be inserted.
The outer shell part may have a through bore extending from the outside of the outer shell part to the inside of the outer shell part for injection of moulding material into the inside of the outer shell part.
The bearing race may be formed by injection of material into the cavity left between the outer shell part and the inner ball part and a recess may be provided on the outer surface of the outer shell part in communication with the cavity to receive material overflowing from the cavity to provide a region in which identification markings may be moulded,